Drop rates are expressed as a percentage when viewing the wiki page of the monster that can drop the item. For example, visiting the wiki page for Leaping Lizzy you would find the drop rates for Bounding Boots expressed like so:

Here we see that Bounding Boots have a drop rate of 7.6%. It is important to note a few things about these drop rates:

• Drop rates are percentages based on fractions of success.
  • When a player experiences success or failure of a drop, it can be expressed as a fraction of successes over attempts, so one drop out of four attempts would be expressed as 1/4.
• All drop rates are estimates based on player experience and are subject to a certain amount of error (both human and statistical error).
  • This means that few drop rates listed are completely accurate, but the more players that add their experiences, the less error in the drop rate.
• Everybody experiences unique drop rates. When you read a 75% drop rate, it is still possible, though highly unlikely that you will go 1/10 on the drop.

The most important thing to remember when it comes to probability is that it is only saying what is probable, not what will be. For instance, when you read a drop rate of 10% (or 1/10) it does not mean you will definitely get a drop by the 10th kill, nor eliminate the possibility of getting it on the first; instead it means that after 10 kills you are, statistically, very likely to have seen a drop.

When you read a drop rate, keep in mind that you are reading the average percentage of success of whatever number of people have contributed their experience. If only 2 people have contributed their experiences the success rate may have an increibly high error rate, but if 2000 people contribute their experience the success rate should be closer to the mark.

Just because a drop rate is 10% and you've killed the monster 9 times without the drop, it does not mean you are due for a drop (a mistake known as the Gambler's fallacy). If you have killed the monster 10 times, the tenth attempt is not any more likely to drop than those attempts leading up to it. If your chances of getting the drop are 10%, then it is 10% every time, whether on the first attempt or the twentieth.

Treasure Hunter

• A job trait obtainable by Thief at level 15 and enhanced at level 45, and again at level 90.
• This is the only confirmed way to enhance drop rates.
• This trait can be improved with a Thief's Knife, Assassin's Armlets or Assassin's Armlets +1, and Raider's Poulaines +2.
• How Treasure Hunter affects drop rates is unkown.

Moon Phase

• It is believed that the moon has a beneficial effect on drops when it is a full moon (90-100%).
• It is believed that the moon has degrading effect on drops when it is a new moon (0-10%).